Piston ring



C. A. MARIEN May 6, 1941.

PISTON RING Filed July 11.,` 1938 A Il.;

Patented May 6, 1941 UNITED STATE compressions, such as Diesels. l beveled cylinder contacting surfaces on the outer 'I'he primary object of the invention is to decast iron ring components; Fig. 3 is a combined vise a piston packing ring that will hold comside elevation and cross-section of a modiiied pression in the cylinder and at the same time form of ring combination differing from that y control the flow of oil over the cylinder wall withshown in Fig. 2 in that the cylinder contacting out an excessive amount of friction such as will surfaces arenot beveled; Fig. 4 is a combined side t produce scoring of the cylinder wall. It is the elevation and cross-section of the inventionempurpose of the present invention to satisfy all the bodied in an oil type piston ring; Fig. 5 is a plan requirements of a piston ring in an engine operatview of the segment of the ring shown in Fig. 2; ing under high compressions and at high speeds. and Fig. 6 is a cross-sectional detail on the line Obviously, the ring must also be serviceable at B--S of Fig. 4. lower compressions and lower speeds as well. In Referring to the drawing, P represents a piston Y other words, it must be efficient throughout the operable within a cylinder C. The piston has a entire range of performance of the engine in series of ring grooves g, g, g' in which are diswhich it is installed. n posed, respectively, compression rings I, l, made Ihave evolved sucharing by combining in vaaccording to my invention, and en oil ring 2 rious ways a thin steel helical ring with a cast embodying the principles of the present inveniron ring. either 0f the empression or Oil type, tion. The'compression ring I (illustrated on an and have accomplished results heretofore incapaenlarged Sonie in Fig, 2) is o, compound ring oonble of accomplishment. sisting of two plain cast iron tapered face ring The subject-matter of the present invention is elements 3, 3 and a. steel element 4 coiled in the a continuation in part 0f that 0f my Patent No. shape of a helix and nested between the elements y 2,128,372, dated August 30, 1938, and has in com- 3, 3,

mOn with that Patent the Combination 0f 8' 1WD- In the present instance two iiat coils a, a which coil spiral steel ring combination with a cast iron are oomparativeiy thin (about sly') comprise ring element. 35 the ring element 4 which is assembled in the I am fully aware that both the thin Steel elegroove g with the ring elements 3,? 3, with lateral ment and the Spiral element are 01d in the art, play or clearance so that the respective ring elethe former being ShOWll in Patent NO. 2,091,947 ments may expand and contract freely as they and the latter in Patent No. 1,165,084. HOWeVer, pass over the cylinder wall during the operation instead of a ring of dished Shape I emDlOy e Del'- 4 of the piston. The compound ring made up of fectly fiat helix, as I have discovered that in prac-` the e1enieni;s 3, 3 and 4 has a, Spring ring 0 1- ex.. ticeA the outer edges of the dished ring cause exponder i; associated with ignnd initially 'in oon.` cessive wear on the groove in Which the ring iS tact with the elements 3, 3, for the purpose'of lodged, ultimately destroying the Shape 0f the augmenting the tension of said elements to in- BrCOVe with deleterious effects- The Same 0b' 45 creasethe unit pressure on 'the tapered faces f, f jeetion applies to a helical ring whichexerts latagainst the cylinder wan. eral pressure against the Sides 0f the Ting groove 'I'he engagement of the springexpander 6 with dus tg :P1151geg'ngggcttelperxyc' the cast iron elements 3, 3, as above described,

r ve gonents rests loosely (without excessive play) in lie pefeggrgnifseni tnl; the piston ring groove so that all contacting suray e Y faces Wm have an ou mm between them to allow spring expander 6 contact initially with the steel for free movement of the respective elements helical element 4. as Well as with the cast iron I without wear on the contacting surfaces. elements 3. 3. However, in no case should the These features, as well as other advantages spring expander contact only with the interme- S PATENT OFFICE 2,129,624 rrs'ron me charles A. Marien, st. Louis. Mo., assigner te i tion, St. Louis, Mo., a corporation o f Missouri Application Ju .y 11, 1938, Serial N0. 218,517 n 4 Clai\ms. (Cl. 309-45) 'I' Ramsey Accesories ltianufaoturing Corpora- My invention has relation to improvements in piston rings and it consists in the novel features of construction more fully set forth in the specication and pointed out in the claims.

While the present invention is primarily adapti ed for use with pistons Within internal combustion engines, lt is equally applicable in many in- Y stances to other types of engines and compressors, especially engines operating at very high' possessed by the invention, will be better apparent from a detailed description of the invenf' tion in connection with the accompanying drawing. in which:

Figure 1 is a side elevation of the upper part of a piston equipped with two different forms of my improved piston ring; Fig. 2 is a combined side elevation and cross-section of my invention embodied in a compression-type piston ring with diate helical element as this would tend to unbalance the ring and reduce the efliciency thereof.

In the modiilcation shown ln'Fig. 3 the cylinder contacting faces ,f',f' of the cast iron ring elements 3f, 3' are square so as to bear iiat against the cylinder wall instead of being tapered as shown in Fig. 2; otherwise the constructions of Figures 2 and 3 are the same.

In the oil type ring shown in Fig. 4 the cast iron ring elements l, I are similar in construction to the cast iron element of my co-pending application aforesaid in thatit has cylinder contacting components 8, 8 maintained in xed spaced relation by triangular shaped pillars 9, across the apex of each of which is a kerf I to enable the oil to ilow readily from one oil passage I I to that next adjacent.

However, the cast iron ring element l, in the prent instance, has the outer edg oi' the cylinder contacting components 8, 8 chamfered as shown at c, c, which reduces the area of the surface initially in contact with the cylinder wall and thereby increases the unit pressure. At the same time, the-lower chamfer c greatly facilitates the operation of inserting the piston into the cylinder. Without the chamfer c, the sharp edge presented is often injured by contact with the cylinder as the ring and piston are inserted into the cylinder.

It will be observed that in Figures 2 and 3 offsets I2, I2 are formed in the opposing side faces I3, I3.of the rings 3, 3 to permit the end portions Il, I4 of the helical element to lie in intimate contact with the outer plain-ring elements 3, 3. In all the forms of the invention herein illustrated and described, lt will be observed that the helical ring is composed of two thin steel coils; whereas, in my pending application, Serial No. 167,680, the thin steel ring is made up of a single coil. struction is that it possesses greater inherent tension so that at very high engine speeds, it responds instantly to the irregularities in the cylinder and remains in intimate contact with the cylinder wall at all times. When this helical ring is combined with a cast iron ring, as illustrated, a compound ring is produced that is effective in holding compression and in controlling the oil flow within the cylinder over the entire range oi engine speeds that the modern automobile engine is capable of and under the high compression ratios at which such engines operate.

The advantage of a helical ring over a plain at ring as shown in my application Serial No. 167,680 is that it is possible to use a helical ring of greater diameter than the diameter of the cylinder. In installing such ring the ring winds in the manner of a watch spring so that its diameter may be reduced suiliciently for installation in the cylinder, after which it-expands against the cylinder wall with sulci nt pressure to fit the wall closely at all points. using a steel ring composed of a single loop the shape thereof, al-

The advantage of the two-coil helical conical rings used alone, as disclosed in the prior art, are ineiective for holding compression because ofthe gap in the helix which permits blow-by. However, when the helical ring is combined with the plain cast iron ring or an oil-type ring, the path for the blow-by is shut ol and the full eciency of the helical ring is realized. In order to obtain these results the helical ring must be at so as to lie squarely against the cast iron ring and without impingement on the side walls of the piston ring groove--in other words, the' entire ring combination must be free to float with the oil film serving as the medium and at the same time assisting in holding compression.

A recapitulation of some of the advantages of my improved ring will show the following:

v2. The ring is capable of efcient performance over a limited range of cylinder sizessince it is capable of expanding to a diameter considerably beyond that of the cylinder. In short, my improved ring fits over-sized cylinders.

3. My improved ring is capable of controlling oil at high piston speeds. 1

4. It prevents blow-by.

5. These advantages become cumulative when a compression-type of'cast iron ring is oombined with the helical ring for one groove of the piston and combined with an oil-type cast iron ring for a lower groove of the piston. As illustrated in the drawing, most advantageous results are obtained in this combination when the helical ring is disposed above the compression-type ring and below the oil-type ring.

Having described my invention, I claim:

l, A three part piston ring comprising a pair of cast iron split rings and a thin steel ring therebetween, said cast iron rings having spaced circumferentially extending rails approximately the width of the steel ring, and the edges of the rails adjacent to the intermediate steel ring being beveled.

2. A three part piston ring comprising a pair of cast iron split rings and a thin steel ring there- Y between, said cast iron rings having spaced circumferentially extending rails, and oil passageways between said rails, and the edges of the rails adjacent to the intermediate steelv ring being beveled, whereby circumferentially extending oil recesses are provided between the steel ring and the cast iron rings.

3. A three part piston ring comprising a pair of cast iron split rings and a thin steel ring therebetween, said cast iron rings having spaced circumferentially extending rails, and the cast iron rings being undercut to provide circumferential recesses adjacent to the intermediate steel ring.

4. A three part piston ring comprising a pair of cast iron split rings and a thin steel ring therebetween, said cast iron rings having spaced circumferentially extending rails to provide oil passageways therebetween, the width of said oil passageways being greater than that of the rails, axd the edges of the rails adjacent tothe intermediate steel ring being beveled to provide knifeedge cylinder contacting surfaces.

CHARLES A.SMARIEN. 

